Pennsylvania’s kindergarten vaccine exemption rate held steady at 6% in the 2025-26 school year, but remains above the national rate, per CDC data.
Why it matters: Pennsylvania’s 307 measles cases this year, nearly 20 times last year’s total and the most in at least three decades, underscore how falling U.S. immunization rates are reviving a disease eliminated in 2000.
The big picture: Vaccination rates among American kindergartners decreased during the 2025–2026 school year for all tracked vaccines, the Centers for Disease Control and Prevention reported on Monday.
- Exemptions from getting one or more vaccines increased in 41 states and D.C, rising nationally to 4.2% from 3.6% the year prior as non-medical exemptions, including philosophical and religious, continue to rise.
By the numbers: In Pennsylvania, vaccination coverage among kindergartners during the 2025-26 school year was 92.7% for measles, mumps and rubella (MMR), 92.6% for polio, and 92.9% for diphtheria, tetanus and acellular pertussis, per CDC data.
- In 2020–21, MMR coverage among Pennsylvania kindergartners was 95.5%, while the state’s vaccine exemption rate among kindergartners was 2.7%, per CDC data.
- Public health officials say overall measles vaccination rates should remain above 95% to maintain herd immunity.
Case in point: Lancaster County is the epicenter of Pennsylvania’s measles outbreak; the county also has some of the state’s lowest student vaccination rates.
- More than half of Pennsylvania’s counties don’t meet the herd immunity threshold for measles.
Zoom out: Kindergarten vaccine coverage decreased in more than half of U.S. states, ranging from 92% for DTaP to 92.4% for MMR and polio vaccines.
- 24 states reported exemptions exceeding 5%.
- MMR vaccine coverage among kindergartners by state ranged from 98.9% in West Virginia to 75.2% in Idaho.
Between the lines: Polling shows childhood vaccines remain popular, but federal efforts to upend longstanding vaccine policies could further erode trust in vaccines and public health, medical experts warn, as vaccine hesitancy continues to rise in the post-COVID era…